U.S. patent application number 10/596837 was filed with the patent office on 2007-06-28 for portable device for receiving media content.
This patent application is currently assigned to KONINKLIJKE PHILIPS ELECTRONIC, N.V.. Invention is credited to David A. Bell.
Application Number | 20070150592 10/596837 |
Document ID | / |
Family ID | 31503815 |
Filed Date | 2007-06-28 |
United States Patent
Application |
20070150592 |
Kind Code |
A1 |
Bell; David A. |
June 28, 2007 |
Portable device for receiving media content
Abstract
A portable device (200, 210) comprises a power source (70) and a
processing system (15, 20, 25, 30, 35) for processing media content
received from a service provider (100) via a delivery channel. A
control apparatus (50, 60) determines remaining capacity of the
power source (70) and receives information from the service
provider (100) about available delivery parameters for an item of
content. The control apparatus determines an operating duration for
the device based on the delivery parameters and the remaining
capacity of the power source and sends a request to the service
provider (100) specifying at least one delivery parameter for
delivery of the content. By specifying what format the service
provider (100) should deliver the content, power savings can be
made in the processing (20, 30) and rendering (25, 35) stages and
in the receive chain of the portable device. Selection of delivery
parameters can be automatic or under user control.
Inventors: |
Bell; David A.; (London,
GB) |
Correspondence
Address: |
PHILIPS INTELLECTUAL PROPERTY & STANDARDS
P.O. BOX 3001
BRIARCLIFF MANOR
NY
10510
US
|
Assignee: |
KONINKLIJKE PHILIPS ELECTRONIC,
N.V.
GROENEWOUDSEWEG 1
EINDHOVEN
NL
|
Family ID: |
31503815 |
Appl. No.: |
10/596837 |
Filed: |
January 11, 2005 |
PCT Filed: |
January 11, 2005 |
PCT NO: |
PCT/IB05/50118 |
371 Date: |
June 27, 2006 |
Current U.S.
Class: |
709/226 |
Current CPC
Class: |
H04L 29/06027 20130101;
G06F 1/3203 20130101; H04L 69/329 20130101; H04L 67/04 20130101;
H04L 67/32 20130101; H04W 52/0229 20130101; H04L 65/4084 20130101;
Y02D 30/70 20200801; H04L 65/80 20130101; G06F 1/28 20130101; H04L
65/602 20130101; H04L 67/303 20130101; H04W 28/18 20130101 |
Class at
Publication: |
709/226 |
International
Class: |
G06F 15/173 20060101
G06F015/173 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 13, 2004 |
GB |
0400658.1 |
Claims
1. A control apparatus for a portable device, the portable device
comprising a power source and a processing system for processing
media content received from a service provider via a delivery
channel, the control apparatus being arranged to: determine
remaining capacity of the power source; receive information from
the service provider about available delivery parameters for an
item of content; determine an operating duration for the device
based on the delivery parameters and the remaining capacity of the
power source; and send a request to the service provider specifying
at least one delivery parameter for delivery of the content, based
on the determination of the operating duration.
2. A control apparatus according to claim 1 wherein the information
received from the service provider includes a duration of the item
of media content and the step of sending a request to the service
provider comprises sending a parameter which will allow the
portable device to operate for a period of time which equals or
exceeds the duration of the item of media content.
3. A control apparatus according to claim 1 wherein the information
received from the service provider indicates a plurality of
alternative delivery parameters for the same item of content and
the control apparatus is arranged to determine an operating
duration for each of the alternative delivery parameters.
4. A control apparatus according to claim 1 which is arranged to
determine an operating duration by making use of stored information
about expected duration.
5. A control apparatus according to claim 4 which is further
arranged to update the stored information based on actual
performance of the portable device.
6. A control apparatus according to claim 1 which is further
arranged to send information about available options for delivery
of the media content to a user interface of the portable
device.
7. A control apparatus according to claim 6 which is further
arranged to receive, from the user interface, a selection of an
available option and the step of sending a request to the service
provider is based on the selection received from the user
interface.
8. A control apparatus according to claim 1 which is further
arranged to send information about the capabilities of the portable
device to the service provider.
9. A control apparatus according to claim 1 wherein the delivery
parameters include at least one of: delivery data rate, video
quality, video format, video resolution, frame rate, colour depth
and audio quality.
10. A control apparatus according to claim 1 wherein the media
content is delivered to the portable device by a streaming
operation.
11. A control apparatus according to claim 1 which is arranged to
automatically send the request to the service provider based on
stored user preferences.
12. A control apparatus according to claim 1 which is arranged to
determine the operating duration and to send the request to the
service provider during delivery of the media content.
13. A control apparatus according to claim 12 which is arranged to
determine the operating duration a plurality of times during
delivery of media content.
14. A portable device comprising a power source, a processing
system for processing media content received from a service
provider via a delivery channel and the control apparatus according
to claim 1.
15. A method of operating a portable device which comprises a power
source and a processing system for processing media content
received from a service provider via a delivery channel, the method
comprising: determining remaining capacity of the power source;
receiving information from the service provider about available
delivery parameters for an item of content; determining an
operating duration for the device based on the delivery parameters
and the remaining capacity of the power source; and sending a
request to the service provider specifying at least one delivery
parameter for delivery of the content based on the determination of
the operating duration.
16. Software for controlling operation of a portable device
comprising a power source and a processing system for processing
media content received from a service provider via a delivery
channel, the software being arranged to cause a processor of the
portable device to perform the steps of: determining remaining
capacity of the power source; receiving information from the
service provider about available delivery parameters for an item of
content; determining an operating duration for the device based on
the delivery parameters and the remaining capacity of the power
source; and sending a request to the service provider specifying at
least one delivery parameter for delivery of the content based on
the determination of the operating duration.
17. A method of delivering media content from a service provider to
a portable device comprising: sending information to the portable
device about available delivery parameters for an item of media
content; receiving a request from the portable device specifying at
least one delivery parameter for delivery of the content, the
parameter being selected by the portable device in response to
determining an operating duration of the device based on the
delivery parameters and the remaining capacity of the power source;
and delivering the item of media content to the portable device
using the requested parameter.
18. A method according to claim 17 further comprising receiving
information about the capabilities of the portable device and the
step of sending information to the portable device sends
information about delivery parameters which are matched to the
capabilities of the portable device.
19. A method according to claim 18 wherein the request is received
during delivery of the media content, and the service provider
changes the delivery parameters of the item part-way during
delivery of the item.
20. A method according to claim 19 further comprising selecting a
point in the delivery of the media content at which to change the
requested parameter.
21. A method according to claim 20 wherein the point is selected
such that it minimises disruption to the delivery of the media
content.
22. A method according to claim 17 wherein the step of delivering
the item of media content is a streaming operation.
23. Apparatus for performing the method according claim 17.
Description
[0001] This invention relates to portable devices which receive
media content from a service provider.
[0002] There is an increasing use of portable devices such as
mobile phones, Personal Digital Assistants (PDAs), portable media
players and portable computers. Portable devices derive their power
from a battery housed within the device, which can be replaced or
recharged when the battery has become discharged. Manufacturers of
portable devices struggle to find a compromise between providing a
battery which has sufficient capacity to provide a useful operating
time for the portable device and providing a battery whose physical
dimensions and weight are small enough that they do not hinder the
portability of the device.
[0003] As additional features are added to portable devices,
devices have increased their power requirements. Portable devices
which are capable of receiving or transmitting streamed content
over the air (e.g. MPEG-4 audio/video) place particularly heavy
demands on the battery. Encoding and decoding of video content is
processor-intensive and makes greater demands on the
transmit/receive chain. The battery life of a third generation (3G)
portable handset can be reduced to little more than 1 hour when
used for video calls.
[0004] Advances in battery technology have increased the capacity
of batteries. However, the increasing demands of devices have
generally overtaken the rate at which battery technology is
evolving.
[0005] US2003/0142087 describes a notebook computer which can
receive both standard definition and high definition broadcast
television signals. The computer calculates a potential viewing
duration and selects one of the two signals, based on the
calculation. This requires multiple channels to be simultaneously
broadcast.
[0006] The present invention seeks to provide a way of operating a
portable device which addresses some of the limitations of using a
limited power source.
[0007] Accordingly, a first aspect of the present invention
provides a control apparatus for a portable device, the portable
device comprising a power source and a processing system for
processing media content received from a service provider via a
delivery channel, the control apparatus being arranged to: [0008]
determine remaining capacity of the power source; [0009] receive
information from the service provider about available delivery
parameters for an item of content; [0010] determine an operating
duration for the device based on the delivery parameters and the
remaining capacity of the power source; and [0011] send a request
to the service provider specifying at least one delivery parameter
for delivery of the content based on the determination of operating
duration.
[0012] The portable device is able to request that the service
provider delivers the content in a manner which is compatible with
the power available to the portable device. Portable devices with a
high-capacity battery or a newly recharged battery are capable of
processing the media content at a high quality while devices with a
smaller capacity battery or a battery which has low remaining
charge will only be capable of processing the media content at a
lower quality. As the portable device indicates its requirements to
the service provider, the service provider can tailor delivery of
the content to a form appropriate to the device. This conserves
bandwidth as the service provider does not need to simultaneously
transmit multiple versions of the same content. By specifying what
format the service provider should deliver the content, power
savings can be made in the processing and rendering stages of the
portable device. Savings can also be made in the receive chain of
the portable device since receiving a lower bit rate stream will
cause the receive chain to consume less power. Power and processing
savings can also be made at the service provider.
[0013] Portable devices which make use of this invention can
include mobile phones, personal digital assistants (PDAs), portable
audio or video players and portable computers. The invention is
most applicable to portable devices which receive content from a
service provider via a network connection, such as a local area
network (LAN), wide area network (WAN) or other communications
network. The delivery channel between the service provider and
portable device can be narrowband or wideband.
[0014] The media content can include audio, still images, video or
any combination of these.
[0015] The functionality described here can be implemented in
software, hardware or a combination of these. The invention can be
implemented by means of hardware comprising several distinct
elements, and by means of a suitably programmed computer.
Accordingly, another aspect of the invention provides software for
controlling operation of a portable device comprising a power
source and a processing system for processing media content
received from a service provider via a delivery channel, the
software being arranged to cause a processor of the portable device
to perform the steps of: [0016] determining remaining capacity of
the power source; [0017] receiving information from the service
provider about available delivery parameters for an item of
content; [0018] determining an operating duration for the device
based on the delivery parameters and the remaining capacity of the
power source; and sending a request to the service provider
specifying at least one delivery parameter for delivery of the
content based on the determination of the operating duration.
[0019] It will be appreciated that software may be installed on the
portable device at the time of manufacture or at any point during
the life of the equipment as an upgrade. The software may be stored
on an electronic memory device, hard disk, optical disk or other
machine-readable storage medium. The software may be delivered as a
computer program product on a machine-readable carrier or it may be
downloaded directly to the portable device via a network
connection.
[0020] Further aspects of the invention provide a portable device
incorporating the control apparatus, a method of operating a
portable device and a method of delivering media content to a
portable device.
[0021] Embodiments of the present invention will now be described,
by way of example only, with reference to the accompanying
drawings, in which:
[0022] FIG. 1 shows a network in which the invention may be
used;
[0023] FIG. 2 shows a portable device embodying the invention;
[0024] FIG. 3 shows a graph of power against time for different
delivery formats;
[0025] FIG. 4 shows a first embodiment of a service provider;
[0026] FIG. 5 shows a second embodiment of a service provider;
and
[0027] FIG. 6 shows signaling between the portable device and the
service provider.
[0028] FIG. 1 shows an example network in which content can be
delivered to portable devices 200, 210. Content is stored at a
service provider of a service provider 100. Portable devices 200,
210 can communicate with the service provider 100 via a connection
which is made across networks 300, 310, 350. Two examples of
wireless access networks are shown. Network 310 represents a
cellular network, such as one based on GSM or UMTS, with switching
centres 311 and base transceiver stations (BTS) 312. Network 350
represents a wireless local area network (LAN) or personal area
network (PAN) which connects to network 300 via a gateway 351. The
wireless connection 355 can be of any suitable type, such as the
IEEE 802.11 family of protocols or Bluetooth. The network 350 may
represent a wireless access point, such as at an airport or other
public place. It will be appreciated that the network connecting
the portable devices 200, 210 to the service provider 100 can take
many other forms and the detail is not important to the present
invention.
[0029] FIG. 2 shows the main functional blocks of the portable
devices 200, 210. An antenna 10 connects to a receive chain 12 and
a transmit chain 14. The receive chain 12 includes conventional
tuning and demodulation circuitry appropriate to the transmission
frequency and format of the wireless signals which are being
received. A demultiplexing function 15 extracts data streams
representing audio, video and other control data from the
demodulated data stream. Audio data is processed by an audio
processing unit 20 and rendered for presentation by an audio
rendering unit 25, which typically includes a digital-to-analog
conversion stage 21, an amplifier 22 and a loudspeaker 23. Video
data is processed by a video processing unit 30 and rendered for
presentation by a video rendering unit 35 which includes a display
32. The audio and video processing units 20, 30 are each capable of
decoding data in a variety of ways. Taking the example of audio,
the audio processing unit 20 can include a particular decoder which
can be operated at a range of possible. bit rates. The audio
processing unit may offer a range of different decoder types, such
as Code Excited linear Prediction (CELP) and Advanced Audio.
Compression (AAC). Similarly, the video processing unit 30 can
support a range of video data bit rates and can offer a range of
different decoder types. Data received from the service provider
specifies the different formats which are available for delivery of
the media content. This data can be received as part of an initial
signalling exchange between the portable device 200, 210 and
service provider 100.
[0030] A wide range of adjustments are possible to a media stream
to reduce the power consumption required at the portable device.
For example, in the `simple` case of receiving and playing a fixed
length stream (e.g. a 30 minute movie) power is being consumed in
receiving the movie data and then in decoding and rendering the
data for presentation. Example characteristics which directly
impact power consumption are: [0031] video resolution--rendering at
the Common Intermediate Format (CIF) of 352.times.288 pixels
requires more power than rendering at the Quarter Common
Intermediate Format (QCIF) of 176.times.144 pixels; [0032] video
frame rate--rendering at 30 frames per second (fps) requires more
power than rendering at 15 or 6 fps; [0033] audio/video
compression--compression algorithms have differing processing
requirements to decompress, which is further affected by settings
specific to that algorithm; [0034] quality--higher quality (i.e.
smooth and no blocks) requires a greater amount of data which in
turn requires a greater amount of processing; [0035] audio
format--stereo requires twice as much processing as mono, assuming
a constant bit rate per channel.
[0036] MPEG-4 defines a range of different profiles and levels for
audio and visual presentation. There are 19 visual profiles which
range from `Simple, Visual Profile` through to `The Core Studio
Profile` and 8 audio profiles. Each profile can also have one or
more quality levels associated with it. The information received
from the service provider 100, identifying what formats the media
content is available in, can be in the form of a set of profile
(and level) numbers. Each profile number, e.g. visual profile #1,
represents a set of parameters for visual delivery and presentation
which are understood by the portable device. Examples of two
profiles established by the Internet Streaming Media Alliance
(ISMA) are:
[0037] ISMA Profile 0: MPEG-4 video simple profile; video
resolution QCIF (176.times.144 pixels) at up to 15 fps; high
quality audio profile (CELP and low complexity AAC); max. data rate
64 kbps;
[0038] ISMA Profile 1: MPEG-4 video simple or advanced simple
profile; video resolution CIF (352.times.288) at up to 30 fps; high
quality audio profile (CELP and low complexity AAC); max. data rate
1.5 Mbps.
[0039] Other profiles can be specified, providing the service
provider 100 and portable device 200,210 both understand what these
represent.
[0040] All of the functions of the portable device are powered by a
power supply 70 which comprises one or more batteries 72. A power
monitoring function 60 monitors the state of the supply 70 and
supplies an output signal 65, representing the remaining power at
any particular time, to a duration processing unit 50. The power
monitoring function uses information about the total capacity of
the battery, together with information about the rate of discharge
to derive an expected remaining capacity.
[0041] Duration processing unit 50 also receives the data from the
service provider 100 about available formats for transmitting the
media content. Duration processing unit 50 uses the information
about available formats, remaining power and data stored in memory
55 to calculate a range of presentation options for the user. The
presentation options are sent to user interface 40. The user
interface can comprise an overlay on display 32 and a keypad (not
shown). Each presentation option includes an estimation of the time
for which the portable device can operate in that option, given the
present state of the power supply 70. It is preferred that at least
one of the options presented to the user will allow the device to
operate for a period which exceeds the duration of the item of
media content. In order to calculate this,. the duration processing
unit 50 makes use of information received from the service provider
about the total duration. of the item of content. Duration
processing unit 50 receives a selection, from the user, of a
presentation option and sends a request, via the transmit chain 14,
to the service provider 100. The request can specify one or more
individual parameters for the streaming operation, based on the
selection made by the user, or a profile (and level) which
represents a set of parameters.
[0042] The different audio and video processing states described
above each consume a different amount of power. Data stored in
memory 55 provides the duration processing unit 50 with information
of estimated presentation duration for a range of different audio
and video states. Preferably, this information is stored in memory
55 as part of the factory set data, which has been derived from
laboratory tests of the portable device and power supply. However,
it is also desirable that the data is updated based on actual
performance of the device. This can be useful as the actual
presentation duration can be less than the expected duration for
reasons such as manufacturing tolerances in the power supply 70 and
processing circuitry, the age of the batteries and factors of the
operating environment, such as temperature.
[0043] FIG. 3 shows one example of a graph of battery capacity (in
mA hours) against time for two different delivery/presentation
profiles. Profile #2 shows an estimated life of 20 minutes while
profile #1 shows an estimated life of 30 minutes. The graph may be
non-linear, particularly as the batteries reach their lowest
capacity. Also, the graph assumes constant operating
characteristics. For a portable device which is moved around an
area, power may be consumed at a greater (or lesser) rate than
expected due to varying distances between the portable device and
serving wireless base stations, which demands a varying transmit
power on the uplink path. Furthermore, lo other features such as a
backlit display will consume additional power. If it is found that
power is being consumed at a greater rate than expected the
portable device can request a further change in the delivery
profile.
[0044] It is preferred that the presentation options sent to the
user interface 40 are greatly simplified. For example, the
different sets of detailed parameters. (bit rate, video quality,
audio quality etc.) can be represented as a simple set of options
with the titles `high quality`, `medium quality`, `low
quality`.
[0045] Memory 55 also stores information about the capabilities of
the portable device. These include the supported audio and video
decoder types, display capabilities (size, colour depth), bit rates
which the receive chain and decoders can support. This information
can be sent to the service provider during an initial signalling
exchange.
[0046] FIG. 4 shows the main features of a first embodiment of
equipment at a service provider 100. Media content is stored on a
server 130. Typically, server 130 comprises an array of storage
devices. Delivery of content from the server 130 is controlled by a
controller 110. Selected content is delivered to a processing unit
150. The processing unit 150 comprises an audio encoder 151 and a
video encoder 152. The encoder units 151, 152 encode the data of
the selected content according to format requirements specified by
the controller 110. The resulting stream of data is multiplexed and
converted into a suitable form for transmission over network 300.
Although media content can be stored in server 130 for selection on
demand, it can alternatively be received from a live feed. The live
feed may represent, for example, a live radio or video broadcast.
In use, the controller 110 can instruct the processing function 150
to select a different delivery format for the same item of content,
in response to a request received from a portable device 200, 210.
Preferably, the change to the new delivery format is as seamless as
possible. A controlled transition from a first to a second format
can be provided by causing delivery of the content in the first
format to end at the same point in the item of content as the
delivery of the second format begins.
[0047] FIG. 5 shows an alternative embodiment of equipment at the
service provider. Data is stored, on server 130, in a plurality of
different formats. The formats can represent different delivery bit
rates. As previously, selection of the particular format of the
content is controlled by a controller 110. In use, the controller
110 can select a different format of the same item of content, in
response to a request received from a portable device, and instruct
the server 130 to deliver the content in the new format.
Preferably, the change of format is as seamless as possible by
coordinating a change between corresponding points, such as a frame
number, in the two versions of the item of content.
[0048] FIG. 6 shows signalling between the portable device 200, 210
and service provider 100. Although not shown, a portable device
would initially receive a directory of available content for
selection. At step 501 the portable device requests a particular
movie clip (movie clip #1). The portable device also sends
information about it's capabilities and requests the possible
options for delivering the clip. At step 502 the service provider
replies with the available profile options. Preferably, the service
provider sends only those profile options which match the
capabilities of the portable device. At step 503 the duration
processing unit 50 of the portable device uses the profile
information received from the service provider, together with
information about the available power supply and stored data to
derive a set of presentation options for the user. Once the user
has selected a particular presentation option it is converted to a
particular profile (in this case, profile #2) and at step 504 the
required profile is requested from the service provider. At step
505 the service provider begins streaming the selected content in
the selected format. During delivery and presentation of the
selected content, the duration processing unit 50 of the portable
device continues to monitor the available power supply. In the
event that the available power supply falls more quickly than
previously anticipated, the user can be presented with a further
selection of possible presentation options (step 506) or the
portable device can automatically select the best option. This
process can be repeated a number of times during the streaming
process to optimise the trade-off between stream quality and
battery life. Considering an example where there is 30 minutes of a
movie clip remaining but there is only 20 minutes of power
available at the present rate of consumption, adjustments can be
made to the stream to lo ensure that the user is able to watch the
entire clip. The screen size can be reduced from CIF to QCIF,
thereby greatly reducing the amount of data being received and
processed. Alternatively, It may be possible to maintain the frame
rate and size of picture but to lower the quality of the picture,
or to reduce only the audio quality. As described above, there are
many different possibilities for reducing power.
[0049] At step 507 the portable device requests a change of format,
in this example to profile #1. At step 508, upon receiving the
request for a format. change, the service provider identifies a
suitable point at which to change the delivery format. At step 509
the service provider begins delivering the content in the new
format. At step 510 the duration processing unit 50 of the portable
device recalculates available presentation duration for the
selected format. At step 511 the streaming ends.
[0050] As described above, the portable device presents the user
with a range of possible presentation options for the media
content. Most of the measures to improve battery life will reduce
quality of the presentation of the media content and so it is
preferred that this trade-off is under the control of the user.
However, the portable device can be arranged to automatically
select a presentation format. The basis for automatically selecting
a presentation option can be:
[0051] (i) a format which will allow the user to view the entire
item of content before the power supply expires. In order to
achieve this, the duration processing unit makes use of information
received from the service provider about the total duration of the
item of content. The portable device may select the best available
format which will allow the user to view the entire item of
content.
[0052] (ii) a format which will use the least amount of power, and
thereby allow the portable device to be used for the maximum amount
of time. Typically, this will be the format with the lowest bit
rate.
[0053] Automatic selection of a format avoids distracting the user
with prompts, which some users may find annoying. The parameters
for automatic selection can be specified by a user as part of the
user preferences for the portable device. It is also possible for
the device to revert to an automatic selection if a user does not
select one of the available options at the user interface within a
predetermined period of time, such as 15 seconds.
[0054] It is described how the capabilities of the portable device
are stored in memory 55 and can be sent to a service provider, such
as during an initial is exchange. In order to reduce the signalling
exchange, and hence bandwidth, the portable device may simply
provide a code corresponding to the capabilities, rather than
listing them in full, or it may refer the service provider to a
location where the service provider can obtain details, such as a
URL. Although it is not necessary for the portable device to
provide the service provider with details about its capabilities,
doing so allows the service provider to respond with delivery
options that are compatible with the capabilities of the portable
device.
[0055] In the above description the service provider 100 is shown
as a single entity. However, in reality the functions of the
service provider may be divided across two or more sites. In
particular, the initial interaction can occur between a portable
device 200, 210 and an internet store front or service gateway,
which then refers the portable device to an appropriate streaming
server which can deliver the content. Servers are typically
distributed geographically to share load.
[0056] It should be noted that the above-mentioned embodiments
illustrate rather than limit the invention, and that those skilled
in the art will be able to design many alternative embodiments
without departing from the scope of the appended claims. In the
claims, any reference signs placed between parentheses shall not be
construed as limiting the claim. The words "comprising" and
"including" do not exclude the presence of other elements or steps
than those listed in the claim. Where the system/device/apparatus
claims recite several means, several of these means can be embodied
by one and the same item of hardware.
[0057] In the description above, and with reference to the Figures,
there is described a portable device which comprises a power source
70 and a processing system 15, 20, 25, 30, 35 for processing media
content received from a service provider 100 via a delivery
channel. A control apparatus 50, 60 determines remaining capacity
of the power source 70 and receives information from the service
provider 100 about available delivery parameters for an item of
content. The control apparatus determines an operating, duration
for the device based on the delivery parameters and the remaining
capacity of the power source and sends a request to the service
provider 100 specifying at least one delivery parameter for
delivery of the content. By. specifying what format the service
provider 100 should deliver the content, power savings can be made
in the processing 20, 30 and rendering 25, 35; stages and in the
receive chain of the portable device. Selection of delivery
parameters can be automatic or under user control.
* * * * *